Cell Specialization

Cartilage Cell

Chondrocytes (from Greek χόνδρος, chondros = cartilage + κύτος, kytos = cell) are the only cells found in healthy cartilage.They produce and maintain the cartilaginous matrix, which consists mainly of collagen and proteoglycans. Although the word chondroblast is commonly used to describe an immature chondrocyte, the term is imprecise, since the progenitor of chondrocytes (which are mesenchymal stem cells) can differentiate into various cell types, including osteoblasts.

Cartilage tissue is found in different parts of the body like in the joints, in the external ear and also between the intervertebral disc. In each part are different types like hyaline, elastic or fibrocartilage.

Hyaline cartilage is cartilage that is transparent.It is pearly bluish in color with firm consistency and has a considerable amount of collagen. It contains no nerves or blood vessels, and its structure is relatively simple. It is covered externally by a fibrous membrane, called the perichondrium.

Elastic cartilage or yellow cartilage is a type of cartilage present in the outer ear, Eustachian tube and epiglottis. It contains elastic fiber networks and collagen fibers. The principal protein is elastin. Elastic cartilage is histologically similar to hyaline cartilage but contains many yellow elastic fibers lying in a solid  matrix. These fibers form bundles that appear dark under a microscope. 

White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its flexibility and toughness to the former of these constituents, and its elasticity to the latter.

Fibrocartilage is found in the pubic symphysis, the anulus fibrosus of intervertebral discs, menisci and the TMJ.